1. Field of the Invention
This invention relates generally to television receivers and, more particularly, is directed to a television receiver for receiving an input signal from either an antenna or an auxiliary device.
2. Description of the Prior Art
With the growing popularity of personal computers and video games, it has become desirable to connect the personal computer or video game to a conventional television receiver so that the picture tube of the receiver may serve as a display device for the video game or personal computer. In this way, the extra expense and wasted space of providing a separate picture tube or CRT for the personal computer or video game are avoided.
A conventional television receiver according to the prior art has a single input terminal for connection to an antenna. The antenna to receives a plurality of RF broadcast channel signals corresponding to different television stations, or channels, and one of the broadcast signals is selected for display on the picture tube by selective actuation of the pushbuttons or a dial mounted on the receiver for easy access. A tuning stage in the television receiver responds to actuation of a push-button, for example, in response to a characteristic tuning voltage provided by actuation of the push-button, for tuning the receiver to a particular channel.
To use the television receiver as a display device for a video game, for example, the output cable of the video game must be connected to the television receiver through the input terminal of the latter and one of the channel-selecting push-buttons must be actuated to tune the receiver for the RF frequency characteristic of the video game output. In order to avoid the necessity of physically disconnecting the antenna and attaching the output cable of the video game to the television receiver everytime it is desired to change from one to the other, an external or auxiliary switching device has been proposed as an accessory interposed between the receiver input terminal and the antenna and video game or personal computer. In one condition of the switching device, the antenna is connected to the receiver input terminal and one of the channel-selecting push-buttons on the receiver may be actuated to select the television signal being broadcast by the respective channel for display on the CRT. In another condition of the auxiliary switching device established by actuation of a condition-selecting push-button or actuating knob on the switching device, the output cable of the video game or personal computer is connected to the receiver input terminals, and another of the channel-selecting push-buttons, for example, one associated with a channel not received at the location of the television receiver, is actuated to tune the receiver for the frequency of the output of the video game or computer. However, the operation of this prior art apparatus presents distinct disadvantages. This apparatus employs switches or push-buttons on two separate objects, that is, the channel-selecting push-buttons on the television receiver and the condition-selecting push-button or knob on the switching device. Change-over from watching a particular TV station to playing a video game requires operation of the condition-selecting push-button on the terminal switching device or accessory, and also actuation of the one of the channel-selecting push-buttons corresponding to tuning for the frequency of the video game output. Similarly, change-over from playing the video game to receiving a desired station or channel on the television receiver requires first that the condition-selecting push-button of the switching device be operated to connect the antenna with the receiver input terminal and then one of the channel-selecting push-buttons must be operated to select the desired channel. Thus, two operations are necessary in changing over from one to the other of the display of the video game and the display of the desired channel.
Additionally, since the prior art apparatus requires two independent devices or housings, that is, the television receiver and the switching device or accessory, the resulting combination may be unsightly and may take up more space than a user wishes to employ for that purpose. Also, it might be necessary, in some instances, to install the switching device at a distance from the television receiver, and the resulting inconvenience to the user in walking back and forth between the two is likely to create consumer dissatisfaction.